Dishwasher



April 30, 1963 H. w. GEscHKA 3,087,504

DISHWASHER Filed April 11, 1961 ZYSheets-Sheet 1 /NrE/yrap H. W. GESCHKA April 3o, 1963 DISHWASHER 2 Sheets-Sheet 2 Filed April ll, 1961 ICT/G. 3

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United States Patent O 3,087,504 DISHWASHER Hugo Werner Geschka, Ginsterweg, Angermund, Germany, assignor to Constructa-Werke G.m.b.H., Dusseldorf, Germany, a corporation of Germany Filed Apr. 11, 1961, Ser. No. 102,170 Claims priority, application Germany Apr. 14, 1960 11 Claims. (Cl. 134-57) The present invention relates to automatic or semiautomatic dishwashers.

yIn conventional dishwashers, the dishes are placed on a grid or in a basket in a washing space. Usually, a sump is provided below the washing space to receive fresh wash water and a chemical cleansing medium to prepare the water for the washing cycle. If the water is to be heated, means may also be provided to heat the sump. A whirlpool wheel may be provided at the bottom of the w-ashing space to throw the prepared wash water continuously against the dishes during the washing cycle whereby dirt is removed from their surfaces. rIhe dirty water runs olf the dishes back into a bottom chamber of the washing space and if this chamber is separated from the space by a sieve retaining the dirt particles and if the water is then returned from this chamber to the washing space by a pump, the dishes will constantly be washed with clean water rather than having the dirty water be thrown against the dishes over and over again. If desired, the pump delivers the clean water from the bottom chamber to shower heads so as to spray the Water into the washing space.

It is also known to mount a special sump in the bottom chamber for preparing the wash water chemically and/ or thermally before it is pumped into the Washing space and to recirculate the prepared water from the washing space into the bottom chamber and back into the washing space. Finally, the spent wash water is removed and the washing cycle may be followed by a rinsing cycle with fresh water. The complete dish washing cycle usually includes a pre-washing cycle, a main washing cycle, a rinsing cycle and a drying cycle, all of which may be controlled by an automatic programming means or by hand.

While conventional dishwashers of the above type are generally satisfactory, the washed dishes are often found to be coated with a grayish, hard calcareous layer. This 'coating is Idue to the calcium content in hard water used for washing the dishes.

It is the primary object of the present invention to prevent calcareous deposits on dishes washed in dishwashers.

This object is accomplished by mounting a water softening ion exchanger in the water inlet conduit means leading to the washing space of the dishwasher. Known water softening cation exchangers bind the calcium in hard water and release sodium chloride in -solution in the Water.

In accordance with a preferred embodiment of this invention, the ion exchanger is mounted within the casing of the dishwasher.

According to another preferred embodiment, means is provided -for indicating the exhaustion of the ion exchange capacity of the ion exchanger and the indicating means operates a programming means designed to cut off further water supply to the dishwasher and thus to stop its operation upon exhaustion of the ion exchange capacity of the ion exchanger. The indicating means may include a counter indicating the number of washing cycles or a means analysing the chemical composition of the ion exchanger, and the programming means may include a switch responsive to the indicating means 4and operating a solenoid valve in the water inlet conduit means to shut olf water supply upon exhaustion of the ion exch-anger.

ICG

I ing to this invention;

IlFlG. 2 is a perspective view thereof;

FIG. 3 is a circuit diagram of an electrical control system of the dishwasher according to this invention; and

FIG. 4 is a control unit for controlling the ion exchange capacity of the water softener.

Referring now to the drawings, there is shown an automatic dishwasher with a casing 1 holding the dish container 2. The container 2, defines the dish washing space 3 and the wash water chamber 4. Space 3 and chamber 4 are separated by sieve 5 which retains solid particles removed from the dishes by the wash water. A drain outlet pipe `6 is mounted on the -bottom of the wash water chamber and communicates with the input of wash water circulation pump 7 the output of which is connected to conduit 8. The conduit or pipe 8 carries one or sever-al shower heads 9 through which the wash water from chamber 4 is forcefully pressed into the washing space 3 during the washing and rinsing cycles.

The machine is supplied with water from a water supply source (not shown) through inlet pipe 10 leading to the water inlet conduit 11 which may be opened and closed by solenoid valve 12 in any suitably programmed manner. The inlet conduit leads from `the valve 12 to a container 13 holding a water softening ion exchange material. The ion exchange material may be any of the well known cation exchange materials used in water-softening processes. Such materials include, by way of example, ion exchange resins with active sulfonic groups which may be converted to the sodium form and will then exchange its sodium ions with the calcium ions present in hard water. Polystyrene -type resins sold by Rohm and Haas Co. under the trademark Amberlite Ill-i are useful for this purpose. O'ther useful cation exchangers include the zeolites which are a class of hydrated silicates of aluminum and sodium compounds of the type Natural zeolites include analcite, chabazite, heulandite, natrolite, stilbite and thompsonite. Artificial zeolites are made in a variety of forms ranging from gelatinous to porous and sandlike. The mineral glauconite has also been found suitable for water softening. Generally speaking, any of the known water softening ion exchangers may be used, including natural and synthetic cation exchange minerals as well as organic cation exchangers, such as -sulfonated phenol-formaldehyde resins and carboxylic -acid resins. All of these water softeners being well known, the present invention is not concerned with any such specific material but with its use in a dishwasher, as herein described.

The ion exchange Water softener placed in container 13 should have an activity suicient to soften about 8 to l0 liters of water per minute.

A conduit 14 connects the container 13` with sump 15 which receives 4the softened water from container 13. A feed pipe 17 leads from funnel 18 to the sump whereby a liquid or solid cleansing medium, such as a detergent `or the like, may be fed to the softened water in sump 15. If cold water is supplied to the machine through inlet pipe 10, the sump may also serve for heating the wash water, for which purpose the sump is shown provided with -an electric heating element 16. This, of course, may be eliminate-d if hot water is supplied to the machine.

At the beginning of kthe washing cycle, the cleansing medium is fed through funnel 18 into pipe 17 which received a stream of water from inlet pipe through the branch pipe 19 which may be opened or closed by valve 20. The sump 15 is connected with the input of circulating pump 7 by conduit 21. At the beginning of the washing cycle, fresh wash water is circulated from sump into conduit 8 and through shower heads 9 into the washing space 3 where the wash water is irnpinged upon lthe dish-es in space 3 and runs off through sieve 5 into the wash water chamber 4. The drain outlet pipe 6 in the chamber 4 returns the wash water to the circulating pump which operates continuously during the main washing cycle -to recirculate the water constantly through the washing space 3.

After the completion of the washing cycle, pump 22, which is connected with drain outlet pipe 6 by conduit 23, is actuated to remove the dirty wash water through outlet pipe 24 from the wash water chamber 4. The circulating pump 7 remains inoperative, of course, while pump 22 operates.

The container 13, which holds the water softening ion exchanger, is connected with funnel 27 by conduit 25, a pivotal lid 28 being mounted in the cover plate 26 of the casing V1 to open and close access to funnel 27. After a certain number of washing cycles, the ion exchanger requires regeneration and, for this purpose, a sodium chloride solution is fed through funnel 27 and flushed under pressure into container 13 whence calcium-rich water is removed through outlet pipe 29 leading from container 13 and being closable by a valve 29a.

The operation of the dishwasher may be programmed in any conventional manner. As shown in FIG. 2, the programming means may include a counter 30 indicating the number of times wash water has been recirculated through space 3. A suitable signaling means, giving a visible or audible signal to indicate -that the ion exchange capacity of the water softener has been exhausted, is provided, as indicated by signal lamp 33. This signal means is operated by counter 30 after a set number of washing cycles predetermined on the basis of the known capacity of the particular ion exchanger used and when it gives a signal, the ion exchanger is regenerated by flushing a common salt solution through pipe 25 and container 13, the outlet pipe 29 being opened at the outlet valve 29a to remove the resultant calcium-rich water. After regeneration, the counter is returned to its zero setting, for instance manually, by setting element 34.

As shown, the exhaustion of the ion exchanger also automatically closes olf any further water supply to the machine from inlet pipe 10. For this purpose, the signal means 33 is connected with a relay operating switch 36 which actuates via lines 35 the solenoid valve 12 in inlet pipe 11 so that the valve is closed upon actuation of signal lamp 33, i.e. when the ion exchange capacity of the water softener in container 13 is exhausted.

As shown in FIG. 2, the dishwasher casing 1 has a front wall 32 with a door 31 through which the dishes are placed in washing space 3 of the machine.

FIG. 3 shows the circuit diagram of an electrical control system for an automatic dishwasher according to the invention.

Electric power is fed .to the dishwasher by power supply lines 42, 44. Valve is connected to power supply lines 42, 44 by lines 46, 48 resp. Line 46 comprises contact 50 of a start butto-n 52. Line 48 comprises a contact 54 actuated by a cam 56 on a shaft 58.

The solenoid valve 12 is also connected to power supply lines 42, 44 by connectors 60, 62. Connector 60 comprises a contact 64 of the starting button 52, connector 62 a contact 66 actuated by a cam 68 on the shaft 58.

Further connected to the power supply lines` 42, 44 is the electrical heating element 16 by connectors 70, 72. Connector 70 comprises a contact 74 of the starting button 52, connector 72 comprises a contact 76 actuated by a cam 78 on the shaft 58.

Further connected to power supply lines 42, 44 is the circulating pump 7 by connectors 80, 82. Connector 82 comprises a contact 84 actuated by a cam 86 on the shaft 5S.

Further connected to power supply lines 42 in the pump 22 by connectors 88, 90. Connector 90 comprises a contact 92 Iactuated by a cam 94 on the shaft 58.

Further connected to power supply lines 42, 44 is a combined `air heater and compressor unit 96 by connectors 98, 100. Connector 100 comprises a contact `102 actuated by a earn 104 on .the shaft 58.

Finally a relay 106 is connected to the power supply lines 42, 44 by connectors 103, 110. Connector 110 comprises a contact 112, actuated by a control unit further to be described. The shaft with `the cams 56, 68, 78, 86, 94, 104 is connected to a reduction gear `116 driven by an electric motor 114. The electric motor 114 is connected by connectors 118', 118 Ito power supply lines 42, 44. Connector 118' comprises a contact 120. This contact 120 is actuated by a level control unit 122. The level control unit 122 comprises a floating body 124 mounted in the wash water chamber 4 (FIG. l).

When the operation of lthe dishwasher is to be started, the starting button 52 is moved to the right in the illustration of FIG. 3. By moving the starting button 52 to the right, contacts S0, 64, 74 are closed. Closing of contact 50 causes opening of the valve 20 as contact 54 is closed. Closing of contact 64 causes energization of solenoid valve 12 as contact 66 is also closed. When the solenoid valve 12 lis energized fresh water is admitted to the dishwasher. Closing of the contact 74 causes power supply to the heating element 16 as contact 76 is also closed. Under these conditions fresh water is admitted into the dishwasher in the way described above. The heating element 16 supplied with electric power heats the water entering into the dishwasher. As soon as a predetermined level in the water chamber 4 is obtained, floating body 124 is raised so as to close contact `120. When contact 120 is closed, the motor 114 starts and drives the cam shaft 58 via the reduction gear box '1.16.

When cam shaft 58 begins to turn, cam 56 yopens contact 54, so that no further water flow takes place through valve 20 and pipe 17. Simultaneously, contact 66 is opened by cam 68, so as to deener-gize solenoid valve 12 and to stop ywater ow through this valve. Cam 86 is so adjusted -as to `close contact 84 before simultaneously with `or after opening of contact 66. When contact 84 is closed, the circulating pump begins to circulate washing water in the dish washer continuously, las already described. During the circulation by the circulating pump 7, cam 78 may continue to keep contact 76 closed, so as to further heat the circulated water by the heating element 16.

As cam shaft 58 is continuously driven by motor 1114 and reduction `gear box 116, contacts 84 and 76 are opened again by the cams 86 and 78 resp. so as to stop operation of the heating element 16 and circulating pump 7. Contact 92 is now closed by cam 94 so as to start pump 22 for conveying the dirty wash water through outlet pipe 24, as already described.

When the dirty wash water has been removed from the dishwasher, contact 92 is opened again, so that pump 22 stops. At `the same time contact 102 is closed by cam 104, :so as to supply power to a motor and a heating element (not shown) of the air heating `and compressor unit 96. After some time when the clean dishes have been dried by the air stream coming from the .air heating and compressor unit 96, contact 102 is opened again so as to interrupt power supply to the air heating and compresser unit. In order to keep closed contact 120 when floating body `124 has once been raised by the wash water, ythere may be a relay, which keeps contact 120 closed, when it has once been closed by floating body 124 and which opens contact 120 again, when the drying action is finished, so as to stop the motor 114.

n FIG. 4 a control unit for controlling the exhaustion of the water softener is illustrated.

Solenoid valve 12 comprises a valve housing 126 land a valve piston 128. The valve pist-on `128 is supported by a magnetic core l130 movable within a magnetic coil 132. The magnetic core 130 comprises an extension 134, which co-operates with a lsprocket 136 on an input shaft 138 ofthe counter 30. An output shaft 140 of the counter 30 bears a lever 142 cooperating with a push rod 143. The push rod 143 acts on a contact 112 of the connector 110 (FIG. 4). The relay 106 (FIGS. 3 and 4) comprises two contacts 144, 146. Contact 144 is normally open and contact 146 is normally closed, when the relay 106 is energized by .the normally closed contact 1l12. When the normally closed contact `112 is opened by the lever 142 and the push rod 143 .the relay 106 is deenergized, so that -contact 144 is closed and contact 146 is opened. Closing of contact 144 causes illumination of a signal lamp 33. Opening of contact 146 prevents further energization of solenoid valve 12.

While a specific embodiment of an automatic dishwasher constructed in accor-dance with this invention has been described, it will be clearly understood that many modifications and variations may occur to the skilled in the art, particularly after benefiting from the present teaching, without departing from Ithe spirit and :scope of the invention as defined in the appended claims.

The output shaft 140 `of the counter 30 actua-tes contact 1i12 after la predetermined number of counting steps transmitted by input shaft 138. Said predetermined nurnber can be varied -by adjusting counter 30. After actuation of contact 112, counter 30 can lbe reset by reset switch 34.

I claim:

l. A dishwasher comprising (a) a casing; and mounted within said casing:

(b) a dish container defining a dish washing space and a wash water chamber below said space;

(c) a wash water drain outlet means in said wash water chamber;

(d) a wash water distributing means mounted in said dish Washing space;

(e) a conduit means connecting the water drain outlet means with the water distributing means;

(f) a water circulation pump in said conduit means for supplying water from the wash water chamber to the dish washing space, the pump having an input connected to the -drain outlet means and an output connected to the distributing means; and

(g) a fresh Water supply and conduit system connected to the input `of the Water circulation pump, said system including (h) a first branch,

V(i) a second branch,

(j) a water sump selectively receiving fresh Water from either of said branches,

(k) a water softening ion exchanger in one of said branches,

(l) a counter lindicating the number of washing cycles lof the dishwasher, and

(m) a signaling means responsive to a number of Washing cycles set in accordance with the predetermined activity o-f the water softening ion exchanger.

2. The dishwasher of claim 1, wherein the first and second branches of the fresh water supply and conduit system lead to said water sump.

3. The dishwasher of claim l, further comprising I(o) a valve in each of said branches for selectively opening and closing said branches.

4. The dishwasher o-f claim 3, further comprising (p) electromagnetic means for opening and closing said valves.

5. The dishwasher of claim 3, further comprising (r) programming means for opening and closing the valves.

6. The dishwasher of claim l, further comprising (s) an inlet means connected to the other one of said branches for introducing a cleansing medium into the fresh water in said other branch.

7. The dishwasher of claim 6, wherein said inlet means is a funnel.

8. The dishwasher of claim 1, further comprising (t) an ion exchange medium inlet means and (u) la conduit connecting the ion exchange medium inlet means with the ion exchanger.

9. A dishwasher comprising (a) a casing; and mounted within said casing;

(b) a dish container defining a dish washing space and a wash water chamber below said space;

(c) a wash water drain outlet means in said wash Water chamber;

(d) a wash water distributing means mounted in said ydish washing space;

(e) a conduit means connecting the water drain outlet means with the Water distributing means;

(f) a water circulation pump in said conduit means for supplying water from the wash water chamber to the dish washing space, the pump having an input connected to the drain outlet means and an output connected to the distributing means;

(g) a fresh Water supply and conduit system -conuected to the input of the water circulation pump, said system including (h) a first branch,

(i) a second branch,

(j) a water sump selectively receiving fresh water from either of said branches,

(k) a water softening ion exchanger in one of said branches,

(l) a counter indicating the number of Washing cycles of the dishwasher, and

(n) a means for stopping the water supply to the dishwasher in response to a number of Washing cycles set on the counter in accor-dance with the predetermined activity of the Water softening ion exchanger.

l0. A dishwasher comprising (a) a casing; and mounted within said casing:

:(b) a dish container defining a dish washing space and :a wash water chamber below said space;

(c) a wash water drain outlet means in said wash Water chamber;

(d) a wash water distributing means mounted in said dish Washing space;

(e) `a conduit means connecting the water drain outlet means with the water distributing means;

(f) a water circulation pump in said conduit means for supplying water from the wash water chamber to the dish washing space, the pump having an input connected to the drain outlet means and an output c011- nected to the distributing means;

(g) a fresh water supply and conduit system connected to the input of the water circulation pump, said system including (h) a first branch,

(i) a second branch,

(j) a water sump selectively receiving fresh water from either of said branches,

(k) a water softening ion exchanger in one of said fbranches,

(o) a valve in each of said branches for selectively `opening and closing said branches;

(p) electromagnetic means for opening and closing the valves;

(l) a counter indicating the number of washing cycles of the dish washer; and

(q) actuating means for said counter, said actuating means being operated by the valve in said one branch.

l1. An automatic dishwasher comprising (a) a casing; and mounted within said casing:

(b) a dish container defining a dish washing space and a wash Water chamber below said space;

(c) a wash water drain outlet means in said wash water chamber;

(d) a Wash water distributing means mounted in said dish washing space;

(e) a conduit means connecting the water drain outlet means with the water distributing means;

(f) a water circulation pump in said conduit means for supplying water from the wash water chamber to the dish washing space, the pump having an input connected to the drain outlet means and an output connected to the distributing means;

(g) a fresh water supply and conduit system connected to the input of the water circulation pump, said system including (v) a water supply conduit,

(h) a irst branch conduit,

(i) a second branch conduit,

(o) valve means between said water supply conduit and said first and second branch conduits,

(j) a water sump selectively receiving fresh Water from either of said branch conduits,

(u) an input conduit connecting the sump to the input of the water circulation pump, and

(k) a water softening ion exchanger in the second branch conduit;

(r) `a programming means sequentially opening said valve means to connect the water supply conduit t0 the first branch conduit, closing said valve means in response to the water level in said wash water chamber, operating said water circulation pump, and finally opening said valve means to connect the water supply conduit to the second branch conduit;

(l) a counter indicating the number of washing cycles of the dishwasher, and

(m) a signaling means responsive to a number of washing cycles set in accordance with the predetermined activity of the water softening ion exchanger.

References Cited in the file of this patent UNITED STATES PATENTS 1,450,054 Titus Mar. 27, 1923 1,525,756 McKenney Feb. 10, 1925 1,910,011 Griswold et al. Mar. 23, 1933 1,963,520 Barker June 19, 1934 2,157,112 Bonner May 9, 1939 2,434,353 Edwards Jan. 13, 1948 2,522,242 Wagner Sept. l2, 1950 2,633,437 Detjen Mar. 31, 1953 2,651,191 Barnes Sept. 8, 1953 2,843,137 Federighi July 15, 1958 

1. A DISHWASHER COMPRISING (A) A CASING; AND MOUNTED WITHIN SAID CASING: (B) A DISH CONTAINER DEFINING A DISH WASHING SPACE AND A WASH WATER CHAMBER BELOW SAID SPACE; (C) A WASH WATER DRAIN OUTLET MEANS IN SAID WASH WATER CHAMBER; (D) A WASH WATER DISTRIBUTING MEANS MOUNTED IN SAID DISH WASHING SPACE; (E) A CONDUIT MEANS CONNECTING THE WATER DRAIN OUTLET MEANS WITH THE WATER DISTRIBUTING MEANS; (F) A WATER CIRCULATION PUMP IN SAID CONDUIT MEANS FOR SUPPLYING WATER FROM THE WASH WATER CHAMBER TO THE DISH WASHING SPACE, THE PUMP HAVING AN INPUT CONNECTED TO THE DRAIN OUTLET MEANS AND AN OUTPUT CONNECTED TO THE DISTRIBUTING MEANS; AND (G) A FRESH WATER SUPPLY AND CONDUIT SYSTEM CONNECTED TO THE INPUT OF THE WATER CIRCULATION PUMP, SAID SYSTEM INCLUDING (H) A FIRST BRANCH, (I) A SECOND BRANCH, (J) A WATER SUMP SELECTIVELY RECEIVING FRESH WATER FROM EITHER OF SAID BRANCHES, (K) A WATER SOFTENING ION EXCHANGER IN ONE OF SAID BRANCHES, (L) A COUNTER INDICATING THE NUMBER OF WASHING CYCLES OF THE DISHWASHER, AND (M) A SIGNALING MEANS RESPONSIVE TO A NUMBER OF WASHING CYCLES SET IN ACCORDANCE WITH THE PREDETERMINED ACTIVITY OF THE WATER SOFTENING ION EXCHANGER. 